The present technology relates to techniques for programming in a resistance-change memory device.
A variety of materials show reversible resistance-change or resistance-switching behavior in which the resistance of the material is a function of the history of the current through, and/or voltage across, the material. A resistance-switching element comprising one of these materials may be formed in an initial state, for example, a relatively low-resistance state. Upon application of sufficient voltage, the material switches to a stable high-resistance state which is maintained even after the voltage is removed. This resistance switching is reversible such that subsequent application of an appropriate current or voltage switches the resistance-switching element to a stable low-resistance state which is maintained even after the voltage or current is removed. This conversion can be repeated many times. For some materials, the initial state is high-resistance rather than low-resistance. A set process may refer to switching the material from high to low resistance, while a reset process may refer to switching the material from low to high resistance. A resistance-switching memory cell can include a resistance-switching element positioned between first and second electrodes.
Reversible resistance-change materials, also referred to as read-write (RW) materials, are of interest for use in nonvolatile memory arrays. One resistance state may correspond to a data “0,” for example, while the other resistance state corresponds to a data “1.” Some of these materials may have more than two stable resistance states.
However, there is a continuing need to advance the development of resistance-change memory devices.